The decree on adoption of the Gregorian calendar approved

On January 24 (February 6) 1918 the Soviet of the People’s Commissars ‘in order to establish in Russia the same time calculation as in the majority of the civilized countries’ adopted a decree ‘On the imposition of the West-European calendar in the Russian republic’.

The pre-revolutionary Russia used the Julian calendar adopted back under Julius Caesar in 45 B.C. which was in effect in all Christian countries until October 1582, when the Europe started to adopt the Gregorian calendar. The latter turned out to be more astronomically attractive since its 24 hours’ divergence with tropic year is achieved just every 3200 years and not every 128 as in the case of the Julian calendar.

The issue of imposing in Russia the Gregorian calendar had been repeatedly discussed since the 1830s. Since the Julian calendar depends on the Easter date and the Gregorian one is based on the astronomic day of vernal equinox, the Russian experts always preferred the first one as the one meeting interests of the Christian state. However in official papers for the international activities as well as in some periodicals it was the rule to indicate the date the both ways.

After the October revolution the Soviet government took a series of measures intended to separate church from state and secularize the social life. Thus at the discussion of the issue of adopting a new calendar system the interests of church were no longer taken into account. The state reasonability was on the forefront.

Since by the moment of the decree adoption the difference between the Julian and Gregorian calendars reached 13 days it was decided that after January 31, 1918 there would come February 14 instead of February 1.

Until July 1, 1918 the decree ordered to indicate in brackets the date according to the former (Julian) style after the date according to the new (Gregorian) style. Later this practice continued but in brackets was indicated the date according to the new style.

To translate the dates from the former to the current style you have to add 10 days to the date of the old style if the event took place within the period from October 5, 1582 to February 29, 1700; 11 days for the period from March 1 to February 29, 1800; 12 days for the period from March 1, 1800 to February 29, 1900; 13 days for the period from March 1, 1900 to February 29, 2100 etc.

According to the existing tradition the events which happened before the appearance of the Gregorian calendar in 1582 are dated according to the Julian calendar. However they also could be translated taking into account the difference having accumulated during the centuries.

Lit.: Декрет о введении западновопейского календаря // Декреты Советской власти. Т. 1. М., 1957; То же [Электронный ресурс].  URL: http://www.hist.msu.ru/ER/Etext/DEKRET/18-01-24.htm; Климишин И. А. Заметки о нашем календаре [Электронный ресурс] // Электронная библиотека Bookscafe.Net. 2015-2016. URL: http://bookscafe.net/read/klimishin_ivan-zametki_o_nashem_kalendare-227133.html#p1.

Based on the Presidential Library’s materials:

The 1st of January is declared a holiday and a day off // On this day. 23 December.